The Immunology Core will serve as a critical component of the "Regulation of Anti-Tumor Immunity" Program, providing services and expertise in both cell isolation and purification and the measurement of antigen specific effector functions. The Core will provide preparative cell isolation using magnetic bead sorting with the autoMACS Separator. The Core will also provide analyses of the frequencies of cells expressing cytokines and other effector molecules (e.g., granzyme) by ELISPOT using the C.T.L. ImmunoSpot automated ELISPOT counter. Lastly, the Core will work with individual investigators on the technical design of cell preparation and animal manipulation and in the interpretation of experimental data.